B.Tech. DEGREE EXAMINATION.Fourth SemesterTextile TechnologyTT 232 — SPUN YARN TECHNOLOGYTime : Three hours Maximum : 100 marksAnswer ALL questions.PART A — (10 ´ 2 = 20 marks)1. What is the use of rib plate in saw ginning?2. Compare the differences between free–flow beating and nipped beating.3. The cleaning efficiency of individual machines of blow room line is 32%, 25% and 40%. Find out the overall cleaning efficiency.4. What are the drawbacks in piano–feed regulating system?5. Explain the influence of feed plate design and its arrangement in carding m/c.6. The count of the lap fed in the carding machine is 0.0015 Ne, the total draft is 95 and the total waste collected is 5%. Find out the count of the delivered silver?7. As the distance between licker–in and mote knife decreases, waste increases. How?8. Preference is not given to reduce roller diameter for controlling floating fibre in draw frame. Why?9. The increase of cop diameter in ring frame does not affect the winding rate. How?10. What is fractionating combing efficiency?PART B — (5 ´ 16 = 80 marks)11. (i) What are the limitations in ring spinning system? And explain how these limitations are overcome by rotor spinning m/c. (12)(ii) In rotor spinning the rotor diameter is 35 cm and its surface speed is 1600 m/s and the yarn is delivered at a speed of 3.2 m/s. Find out the twist/inch on the yarn. (4) (a) (i) Explain the working principle of ERM cleaner. (12) (ii) The length of the lap is 37 m and its weight is 18 kg. Find out the hank of the lap. (4)Or(b) (i) Explain the working principle of Krischner beater. (12) (ii) Bring out the differences between hopper bale opener and hopper feeder. (4)12. (a) (i) What is blending evenness? (4) (ii) How it is obtained in Rieter UNImix? (12)Or(b) (i) Explain in detail how the fibres are individualised and neps are disentangled in carding machine. (10) (ii) The diameter of feed roller is 2 inches and its speed is 5 rpm, the diameter of licker–in is 9 inches and its speed is 450 rpm the feed count of the lap is 0.0015 Ne and micronaire value of the fibre is 3.4. Find out the draft between licker–in and feed roller. Calculate the number of fibres in the cross section of licker–in delivery material. (6)13. (a) (i) What is drafting wave? (2) (ii) What is polar drafting? And explain the reason for inventing this system. (14)Or(b) (i) Draw the clear diagram of simplex builder mechanism. (8) (ii) Explain the shape of the bobbin and how it is formed in simplex m/c. (8)14. (a) (i) Explain the working principle of friction spinning system. (12) (ii) Compare the twisting process of friction spinning and ring spinning. (4)Or(b) (i) Why even numbers of passages are required between carding and combing? Explain in detail. (12) (ii) Combed slivers are mostly preferred to produce finer count. Why? (4)————————